Core drill bit



July 12, 1932.

G C. OLIVER CORE DRILL BIT Filed Jan. 23, 1929 GTT'OBNEY Patented July 12, 1932 UNITED STATES PATENT OFFICE GUY C. OLIVER, OF WHIT'IIER, CALIFORNIA, ASSIGNOR OF ONE-THIRD TO B. M. COMBS, OF WHITTIER, CALIFORNIA, AND ONE-THIRD 'I'O E. A. SPENCER, 01 LOS ANGELES,

CALIFORNIA CORE DRILL BIT Application filed January 28, 1929. Serial No. 334,877.

This invention relates to a drill bit which is particularly adapted for use in combination with rotary drilling equipment for the drilling of bore holes such as 011 wells or the like.

his a primary ob ect of this inventlon to produce a bit of this character which 1S f simple form and construction and embodles novel structural features which are adapted 1 to increase its efliciency and durabillty over the bits now in use in the industry.

' Briefly described this bit embodies a body member, the lower end of which is provlded with cutting blades, spaced apart-to admit the upward passage of a central portion of the formation in which the bit is operatmg. The body member is provided with a central passage which curves outwardly and ejects the-so-called core of material cut by :0 the blades into the bore hole where it is washed away by the circulating fluid.

It is a noteworthy feature of the invention that the body member is provided with means for delivering a circulating fluid from the drill string downwardly about the mentioned passage and against the cutting blades,

further that means may optionally be provided for directing a part of the circulating fiuid into the central passage to wash the 90 cored material into the bore hole.

It is another important feature of the invention that the central passage is 'preferably made funnel shaped, having the largest diameter at the upper outlet end in the peripheral wall of the body member, and that the curvature of the passage is so slight as to offer very little resistance to the upward and outward movement of the cored material.

It follows therefore as a further object of this invention to produce a bit of the class described which may be thought of as cutting an annular channel into the formation, and at the same time washing the core material, which is left in the center of the channel, to the surface of the ground by means of a circulating fluid thereby reducing the area of surface actually out by the bit.

This construction therefore permits the cut- 60 ting blades to wear uniformly (the ordinary fish tail bit wearsto a diamond point), it

increases the drilling speed and may, if desired, be used to remove a small sample of the formation into which the bit is penetrating it lthe time it is withdrawn from the bore The details in the construction of my invention together with other objects attending its production will be better understood from the following description of the accompanying drawing in which;

Fig. 1 is a sectional elevation showing an embodiment of the invention and illustrating the manner in which the invention would operate in passing through an underground formation.

Fig. 2 is a plan section taken substantially in a plane represented by the line 22 in Fig. 1.

Fig. 3 is a plan section taken substantially in a plane represented by the line 3-3 in F ig. 1.

Fig. 4 is an inverted plan view of the cutter head used in that form of my invention shown in Fig. 1.

Fig. 5 is a sectional elevation of a modified form of my invention in which the body member and the ejecting passage are made in a single unit.

Fig. 6 is a plan section taken substantially in a plane represented by the line 6-6 in Fig. 7 is a plan section taken substantially in a plane represented by the line 7-7 in Fig. 5; and

Fig. 8 is a plan section taken substantially in a plane represented by the line 8-8 in Fig. 5.

More particularly describing my invention as herein illustrated, reference numeral 11 indicates a body member which is suspended from the lower end of a drill string 12. The lower end of the body member 11 is provided with a plurality of blades 13, the inner edges 14 of which are spaced apart to admit the upward passage of material cored from the formation as indicated at 15.

The body member 11 is also provided with a substantially uninterrupted and slightly curved passage 16, the lower end 17 of which provides an inlet for the cored material 15,

and the upper end 18 of which is positioned in the peripheral Wall of the body member,

providing an outlet through which the cored material is ejected into the bore hole, and from which point this material is washed to the surface of the ground by means of circulating fluid.

In the form of the invention shown in Figs. 1 to 4 inclusi e, the passage 16 is illustrated as being in the form of a curved funnelshaped tube 20, the upper outer end of which is of larger diameter than the lower end, and which may be welded, brazed or otherwise secured within a suitable aperture 21 formed in the peripheral wall of the body member.

The body member itself is provided with a central longitudinal passage 22, which receives the tube 20, and which also communicates with a fluid circulating passage 23 in the drill string.

The blades 13 are illustrated as being mounted upon a removable head 130: which facilitates their removal for sharpening, and the lower inner edges of the blades are provided with shoulders 24 which bear against the lower edge 25 of the tube and increase the rigidity of the unit.

It will be noted that the lower end of the tube 20 is made of less outer diameter than the inner diameters of the lower end of the body 11 and the head 24., and this constructionleaves an annular passage 26 above the lower edge of the blades, and admits the direct delivery of circulating fluid into the annular groove or channel being cut by the blades, for cooling the blades and washing the cuttings from the hole.

The upper inner end of the passage 16 54 may be provided with a breaker blade or finger 28 which is adapted to assist'in the breaking up of the material passing through the passage, and'means such as the auxiliary passage or orifice 29 may be provided in the '4 tube 20 for diverting a part of thecirculatin fluid into the passage 16 to wash material into thebore hole. Figs. 5 to 8, inclusive, illustrate a modlfied the core form of the invention in which the parts similar tothose described in connection with Fig.

1 are indicated by the same reference numerals distinguished by the prime mark, but in which the body member 11 is illustrated as comprising a single unit having the passage 1 16 cast or otherwise formed therein.

v. .3 adapted to receive a suitable sub or bushing 36 by means of which the body member 11' issuspended from a-drill string 12.

Circulating fluid" is delivered from the chamber 35 to the blades 13 through a lu- 9.5 rality of passages 37 which deliver such uid gers 40 which will break 011' the formation when the bit is removed and will leave a. clean hole for continuing the drilling operation. The material in the bit after it is withdrawn from the well may be removed and will give an indication of the type of material which is being penetrated at the point at which the drilling operation ceased.

Although I have herein described and illustrated a preferred form and a modification of my invention, various changes might be made as, for instance, providing a plurality of outlet passages for ejecting the cored material into the bore hole, and it will therefore be understood that the invention is not confined to the precise construction set forth but includes within its. scope whatever changes fairly come within the spirit of the appended claims.

I claim as my invention:

1. A drill bit embodying: a body member having cutters on its lower end and provided with a substantially uninterrupted passage extending between said cutters and through the peripheral wall of said body, means for delivering a circulating fluid through said body to the cutting'edge of said cutters, and means for diverting a part of said circulating fluid into said passage.

2. A drill bit for use in underground bore holes embodying: a body member adapted to be suspended from the lower end of a drill string; cutters on the lower end of said body member having their inner edges spaced apart; a tubular member in said body having an inlet opening between said cutters and an outlet opening in the periphery of said body above said cutters; means for delivering a circulating fluid through said body to the cut? ting edge of said cutters; and means for diverting a part of said circulating fluid into said tubular member.

3. A drill bit embodying: a. body member having a circulating fluid passage there-' through; a tubular memberarranged in said passage to formasubstantially uninterrupted passage from the lower end of said body memher to a peripheral wall there0f, said tubular member having an opening in the upper portion thereof communicating with said first mentioned circulating fluid passage.

4. A body member having a fluid circulating passage therethrough a tubular member adapted to receive a core arranged in said passage to form a substantially uninterrupted passage from the lower end of said body member to a peripheral wall thereof; means in the vupper portion of said tubular member for breaking said core; and means for diverting apart of said circulating fluid to the u per portion of said tubular member to ush said broken core.

In testimony whereof, I have hereunto set 5 my hand at Los Angeles, California, this 15th day of January, 1929.

GUY C. OLIVER. 

